1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Help with quantum physics

  1. Mar 30, 2016 #1
    < Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown >

    Hello guys, i need some help in clarifying a question.

    A beam of ultraviolet light with wavelength of 200nm is incident on a metal whose work function is 3.0eV. Note that this metal is applied with +1.0V with respect to the ground, Determine the largest kinetic energy of the photoelectrons generated in this process.

    Using the formula of KEmax = hf - work function, i can come up with an answer for it. However, from the question, it states the metal is applied with +1.0V with respect to the ground;Does this Voltage affect the KEmax? Because if i were to find stopping potential Vs using E=q|Vs|, Vs will result in approximately 6.211V, taking q to be 1.6 x 10^-19. So i believe that this voltage across the metal is redundant in the calculation.

    Kindly advice.

    Thank you guys!
     
    Last edited by a moderator: Mar 30, 2016
  2. jcsd
  3. Mar 30, 2016 #2

    DrClaude

    User Avatar

    Staff: Mentor

    So if the applied potential was 6.211 V instead of 1 V, what would you answer for KEmax?
     
  4. Mar 31, 2016 #3
    Won't it be the same as KEmax?
     
  5. Apr 3, 2016 #4
    I'm quite confused, is it alright to assume that the applied +1V on the metal is also the stopping voltage? And does this applied voltage on the metal makes it harder for the electrons to break the bond from metal -> Vacuum -> Being ejected ?
     
  6. Apr 6, 2016 #5

    DrClaude

    User Avatar

    Staff: Mentor

    No. As said, the stopping potential is 6.211 V.

    No. It changes what happens to the freed electron.
     
  7. Apr 6, 2016 #6

    DrClaude

    User Avatar

    Staff: Mentor

    What is the definition of the stopping potential?
     
  8. Apr 6, 2016 #7
    I had this question figured out. Thanks!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Help with quantum physics
  1. Quantum Physics Help (Replies: 1)

  2. Quantum Physics HELP (Replies: 1)

Loading...